Innacuracy in Carbon -14 dating

[Cap'n Refsmmat]

I've heard of a lot of people saying "oh carbon dating is innacurate and they dated rock that just came out of a volcano and it was 1393321943 years old and how can that be right" and blah blah blah. So, I'd like to know just how innacurate it is, even though I know (from here) that those claims are pretty much wrong. Read the link BEFORE YOU POST!!!!!!!!

Oh, and if you have any claims about how innacurate it is, tell me, I'd like to hear them.

[admiral_ju00]

Bleh. You should know better than to listen to the creationist mumbo-jumbo. Reading it for fun is one thing(and I do that for sheer boredom), but taking things to heart is quite another.

 

C14-C12 dating is very accurate until 40,000 years of age.

The half life of C14 is about 5,700 years, and the problem with using the C14-C12(or simply Carbon 14 dating techniques) is that past 40,000 years(you may be able to push it to 45, but stop there), the element, rock, fossil, what have you, has about 2% of Carbon left it in. At that small of an amount, it's difficult to tell if the sample was contaminated or not. That's where the Potassium-Argon comes in or the K-40 test, which has a half-life of about 1.25 billion years.

Also, the C14 test is very, very accurate at dating stuff past 10,000 years of age. Lots of Archaeologists and Anthropaleontologists will swear by it's accuracy.

 

Also, it depends on where you get your samples. The best items that you can use the C14 test are those that came from volcanic areas. If the sample(say a rock) was under water(in particular the salt water), then that changes things dramatically, and things are not accurate at all.

 

The problem is that if the sample is contaminated, or the environment is simply not fit for a C14 test on an item you suspect is upto 40-45k years, then other less reliable testing methods are used. Some of those are the Electon Spin Resonance, Thermoluminance, etc. But if that's all you can use, then do it.

[5614]

i always thought when i learnt it in school:

 

"how accurate can it be????"

 

but by the seems of things, the people who do it [carbon dating] seem certain it is accurate, and so does everyone else, so i believe them!

[and so does the admiral, so thats more proof it is accurate!]

[swansont]

C14-C12 dating is very accurate until 40' date='000 years of age.

The half life of C14 is about 5,700 years, and the problem with using the C14-C12(or simply Carbon 14 dating techniques) is that past 40,000 years(you may be able to push it to 45, but stop there), the element, rock, fossil, what have you, has about 2% of Carbon left it in. At that small of an amount, it's difficult to tell if the sample was contaminated or not. That's where the Potassium-Argon comes in or the K-40 test, which has a half-life of about 1.25 billion years.

Also, the C14 test is very, very accurate at dating stuff past 10,000 years of age. Lots of Archaeologists and Anthropaleontologists will swear by it's accuracy.

 

Also, it depends on where you get your samples. The best items that you can use the C14 test are those that came from volcanic areas. If the sample(say a rock) was under water(in particular the salt water), then that changes things dramatically, and things are not accurate at all.

[/quote']

 

I was under the impression that you don't use C-14 to date rocks or fossils. Only organic matter. Do you have cites to the contrary?

 

([nitpick]Also, at 40k years, you have less than 1% of the C-14 remaining.[/nitpick])

[admiral_ju00]

I was under the impression that you don't use C-14 to date rocks or fossils. Only organic matter. Do you have cites to the contrary?

 

Lol. I suppose that was a poorly chosen example as far as the rocks thing.

However, the Carbon-14 test is used on fossils as depending on the age of the fossil (it's location in the strata, exposure to contaminants, etc), it does still have *some* organic matter on/in it. Ofcourse once the fossil is mostly N-14, the Carbon-14 is useless on it. For example, to date, the oldest fossil out of which a successful extraction of mtDNA was done is dated to just about 50,000 years old.

 

([nitpick]Also, at 40k years, you have less than 1% of the C-14 remaining.[/nitpick])

 

You nitpicking Physicists.

Filthoids, all of ya.

Just kidding.